Merge pull request #8232 from vbatts/vbatts-devmapper_getDeps

devmapper: include dm_deps information in debug

daemon/graphdriver/devmapper/deviceset.go

@@ -771,10 +771,15 @@ func (devices *DeviceSet) deactivatePool() error {
 	log.Debugf("[devmapper] deactivatePool()")
 	defer log.Debugf("[devmapper] deactivatePool END")
 	devname := devices.getPoolDevName()
+
 	devinfo, err := getInfo(devname)
 	if err != nil {
 		return err
 	}
+	if d, err := getDeps(devname); err == nil {
+		// Access to more Debug output
+		log.Debugf("[devmapper] getDeps() %s: %#v", devname, d)
+	}
 	if devinfo.Exists != 0 {
 		return removeDevice(devname)
 	}

daemon/graphdriver/devmapper/devmapper.go

@@ -51,6 +51,7 @@ var (
 	ErrTaskSetRo              = errors.New("dm_task_set_ro failed")
 	ErrTaskAddTarget          = errors.New("dm_task_add_target failed")
 	ErrTaskSetSector          = errors.New("dm_task_set_sector failed")
+	ErrTaskGetDeps            = errors.New("dm_task_get_deps failed")
 	ErrTaskGetInfo            = errors.New("dm_task_get_info failed")
 	ErrTaskGetDriverVersion   = errors.New("dm_task_get_driver_version failed")
 	ErrTaskSetCookie          = errors.New("dm_task_set_cookie failed")
@@ -75,6 +76,11 @@ type (
 	Task struct {
 		unmanaged *CDmTask
 	}
+	Deps struct {
+		Count  uint32
+		Filler uint32
+		Device []uint64
+	}
 	Info struct {
 		Exists        int
 		Suspended     int
@@ -171,6 +177,14 @@ func (t *Task) AddTarget(start, size uint64, ttype, params string) error {
 	return nil
 }
 
+func (t *Task) GetDeps() (*Deps, error) {
+	var deps *Deps
+	if deps = DmTaskGetDeps(t.unmanaged); deps == nil {
+		return nil, ErrTaskGetDeps
+	}
+	return deps, nil
+}
+
 func (t *Task) GetInfo() (*Info, error) {
 	info := &Info{}
 	if res := DmTaskGetInfo(t.unmanaged, info); res != 1 {
@@ -392,6 +406,17 @@ func createTask(t TaskType, name string) (*Task, error) {
 	return task, nil
 }
 
+func getDeps(name string) (*Deps, error) {
+	task, err := createTask(DeviceDeps, name)
+	if task == nil {
+		return nil, err
+	}
+	if err := task.Run(); err != nil {
+		return nil, err
+	}
+	return task.GetDeps()
+}
+
 func getInfo(name string) (*Info, error) {
 	task, err := createTask(DeviceInfo, name)
 	if task == nil {

daemon/graphdriver/devmapper/devmapper_test.go

@@ -3,8 +3,9 @@
 package devmapper
 
 import (
-	"github.com/docker/docker/daemon/graphdriver/graphtest"
 	"testing"
+
+	"github.com/docker/docker/daemon/graphdriver/graphtest"
 )
 
 func init() {

daemon/graphdriver/devmapper/devmapper_wrapper.go

@@ -38,9 +38,7 @@ static void	log_with_errno_init()
 */
 import "C"
 
-import (
-	"unsafe"
-)
+import "unsafe"
 
 type (
 	CDmTask C.struct_dm_task
@@ -92,6 +90,7 @@ var (
 	DmTaskAddTarget        = dmTaskAddTargetFct
 	DmTaskCreate           = dmTaskCreateFct
 	DmTaskDestroy          = dmTaskDestroyFct
+	DmTaskGetDeps          = dmTaskGetDepsFct
 	DmTaskGetInfo          = dmTaskGetInfoFct
 	DmTaskGetDriverVersion = dmTaskGetDriverVersionFct
 	DmTaskRun              = dmTaskRunFct
@@ -168,6 +167,21 @@ func dmTaskAddTargetFct(task *CDmTask,
 	return int(C.dm_task_add_target((*C.struct_dm_task)(task), C.uint64_t(start), C.uint64_t(size), Cttype, Cparams))
 }
 
+func dmTaskGetDepsFct(task *CDmTask) *Deps {
+	Cdeps := C.dm_task_get_deps((*C.struct_dm_task)(task))
+	if Cdeps == nil {
+		return nil
+	}
+	deps := &Deps{
+		Count:  uint32(Cdeps.count),
+		Filler: uint32(Cdeps.filler),
+	}
+	for _, device := range Cdeps.device {
+		deps.Device = append(deps.Device, (uint64)(device))
+	}
+	return deps
+}
+
 func dmTaskGetInfoFct(task *CDmTask, info *Info) int {
 	Cinfo := C.struct_dm_info{}
 	defer func() {